Pulverized-fuel-feeding device.



A. D. HEYL.

PULVERIZED FUEL FEEDING DEVICE.

APPLICATION FILED SEPT. 23, I914.

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OF NEW YORK, N. Y., ASSIGNOR TO QUIGLEY FURNACE AND FOUNDEY COMPANY, A CORPORATION OF MASSACHUSETTS.

PULVERIZED-FUEL-FEEDING- DEVICE.

Specificatiori of Letters Patent.

Patented July f3, 1215.

Application filed September 23, 1914. Serial No. 863,216.

To all whom it may concern:

Be it known that I, ALBERT D. HEYL, a citizen of the United States of America, residing at New York city, county and State of New York, have invented certain new and useful Improvements 'in, -Pulverized- Fuel-Feeding Devices, of which the following is a specification.

My invention relates to apparatus for feeding finely divided material, such as pulverized coal whichis delivered to furnaces upon a current of air.

It constitutes animprovement on the type of apparatus shown and described in patent to J. V. Gulliney, No. 784,307, dated March 7, 1905. In pulverized coal feeders or controllers of this type the coal dust is fed out from under a hopper at a regular rate'by a screw conveyer and over an opening into an air conduit chamber, into or through which it drops, and in which it meets a, transverse current of air entering at one side and passing'out at the other. The desired quantity of fuel is carried away' on this transverse air current, while the surplus, if any, falls to a lower conduit, where a return screw conveyer forces such surplus back to the hopper. In the patented form of apparatus above described the rate of delivery to the air conduit chamber is constant for a given rate of rotation of the feed screw, and the only way in which such rate of delivery can be varied is by changing the driving gears, or the speed of the motor driving the screws. Either of these is a matter of some'difiiculty' under certain con ditions, and usually only gives a step by step ad; 'istment. As a result, any finer adjustment of the amount of fuel carried away by the air blast must be secured by regulating the volume or speed of the air current itself. This makes two adjustments necessary to secure the .full range of regulation.

My invention reduces the matter of such regulation or control of the fuel to the movement of a single gate, leaving both the conveyer screws and the air blast to operate at constant rates. 1

The best form of apparatus embodying my invention at present known to me, and one modification thereof, are illustrated in the accompanying sheet of drawings in which,

Figure l is a side elevation and partial vertical section (with parts broken away) of a controller of the Culliney type. modified to operate according to my improved method. Fig. 2 is a cross section taken on line 2-2 of Fig. 1. Fig. 3 is a detail section on the plane of Fig. l, showing a-modification, and Fig. 4 is a cross section on the same plane as Fig.

' 2, also showing said modification.

Throughout the drawings like reference I The passageway 4, is I the source of supply, the two conduits and conveyer mechanism therein, and the surplus chamber, constitute a closed circuit or path for the circulation of the pulverized coal or other material, which is constantly open, and of a capacity to handle the maximum quantity ever required.

The air conduit chamber 8, is next to the surplus chamber, on the side toward the hopper 1. This has its opening 9, from'the bottom of feed conduit 3, controlled by gate 10. When the gate is open the chamber 8, constitutes a bypass across the closed path of circulation above described. The transverse air current enters this chamber 8, by pipe 11, and passes out by pipe 12.

In operation the conveyer screws are run at a constant speed sufiicient to deliver the maximum quantity of coal which can be .handled, and theair blast is also supplied will drop to the return screw conveyer 6.

Thus the entire supply of fuel to the furnace.

can be instantly turned on or cut off with out disturbing the regular operation of the screw driving mechanism or the air blast. When the gate is half opened, as shown in Fig. 1, half the coal is dropped into the air conduit chamber to be carried away to the furnace, while the remainder passes through surplus chamber 4, to the return conveyer 6, and back to the magazine at the bottom of the hopper. By intermediate adjustments of' gate 10, any rate of delivery from zero to maximum can be instantly secured with exactness.

In Figs. 1 and 2, gate 10, is adjustable longitudinally of the controller. In the -;modification shown in Figs. 3 and. 4, a similar gate 13, is adjustable transversely of the controller. Otherwise the operation is the same.

The advantage of my invention arises ciple of operation here set out in one form of embodiment. Also the connection between the air conduit chamber and the return conduit 5, might be dispensed with.

without departing from the underlying prin-- Having, therefore, described my invention, I claim:

1. In an apparatus for feeding finely di-' vided material the combination of a hopper, a feed conduit and a return conduit extending from said hopper, conveyer screws therein, a surplus chamber connecting the two conduits, an air conduit chamber connected to the feed conduit between the hopper and the surplus chamber, and an adjustable gate controlling such connection to the air conduit chamber.

2. In an apparatus for feeding finely divided material the combination of a source of supply, a feed conduit extending therefrom, a return conduit connected to the feed conduit by a permanently open passageway and leading back to the source of supply,

continuouslv acting conveving means in said conduits, a bypass connecting said conduits located between the permanently open passageway and the source of supply, conveying means connected with said by-pass, and mechanism for controlling the opening between the feed conduit and the by-pass.

- 3. In an apparatus for feeding finely divided material the combination with mechanism for circulating a given quantity of material through a constantly maintained closed circuit of fixed capacity, of a by-pass across said circuit, conveying means connccted with said by-pass, and means for adj usting the opening to said by-pass.

ALBERT D. HEYL.

M. K. LOTTERER'.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

